Morphology- and Porosity-Tunable Synthesis of 3D Nanoporous SiGe Alloy as a High-Performance Lithium-Ion Battery Anode.

The lithium storage performance of silicon (Si) can be enhanced by being alloyed with germanium (Ge) because of its good electronic and ionic conductivity. Here, we synthesized a three-dimensional nanoporous (3D-NP) SiGe alloy as a high-performance lithium-ion battery (LIB) anode using a dealloying method with a ternary AlSiGe ribbon serving as the precursor. The morphology and porosity of the as-synthesized SiGe alloy can be controlled effectively by adjusting the sacrificial Al content of the precursor. With an Al content of 80%, the 3D-NP SiGe presents uniformly coral-like structure with continuous ligaments and hierarchical micropores and mesopores, which leads to a high reversible capacity of 1158 mA h g-1 after 150 cycles at a current density of 1000 mA g-1 with excellent rate capacity. The strategy might provide guidelines for nanostructure optimization and mass production of energy storage materials.